Industrial knitting machines, and particularly circular knitting machines, are of complex, precision construction. They require the attention of skilled operators to ensure that the fabric generated is produced at an optimum rate and is of first quality.
A circular knitting machine includes a plurality of needles arranged in a circular pattern around the perimeter of a cylinder. The needles are provided with yarn. As the cylinder rotates and the needles reciprocate a knitted tubular fabric is developed and is withdrawn from below the needle cylinder.
Because of the constant motion of the needles and associated elements, they must be lubricated and cooled. Physically, such lubrication is provided by an oiling apparatus, the operation of which must be carefully controlled and monitored. Over-lubrication can result in unacceptable fabric spotting and staining, while under-lubrication can result in seizing or jamming of the needles. The importance of adequate heat removal continues to grow as the knitting speed of the machines increases.
The control of dust is another area of concern. The accumulation of dust and lint on or about the needles and associated mechanisms can jam or otherwise disrupt proper operation of the knitting machine. In addition, the capture of lint and dust by the knitted fabric lessens its quality.
Typical dust control apparatus include rotating fans which direct a sweep of air across the knitting machine operating areas. In addition, the use of pressurized air streams and/or suction devices in the proximity of the needle cylinder has been attempted to remove lint and dust from such areas. Such pressurized air devices also serve a cooling function, assisting the lubricating oil in such a regard. Conventional pressurized air and vacuum and suction systems are typically of rigid construction, and either constructed and arranged as an integral part of the knitting machine, or intended to be rigidly fastened and attached thereto. In either case, as a pressure/suction system should surround and enclose the needle cylinder area of the machine to operate effectively, such a system requires mechanical disassembly and removal from the knitting machine for knitting machine maintenance. This represents a significant shortcoming to the use of such systems, as knitting machine operators often require access to the needle area, either to replace a broken needle, restart a broken yarn strand, or otherwise adjust operations. A requirement to disassemble an air supply system to afford access to the knitting machine components blocked thereby, increases the downtime of the knitting machine and can complicate the adjustment or repair process.
It is accordingly a purpose of the present invention to provide a pressurized air cooling and dust control system for a circular knitting machine which may be easily mounted to a knitting machine.
Yet a further purpose of the present invention is to provide an air cooling and dust control system for a circular knitting machine which, when not operating, does not obstruct access to the needle cylinder and dial area.
Still a further purpose of the present invention is to provide a system of the aforementioned type which provides a visual indication of the degree of airflow passing therethrough.
Another purpose of the present invention is to provide a cooling and dust control system of the aforementioned type which can dynamically seal the needle cylinder and dial area of a circular knitting machine when in operation and retract to a rest position when not in use.